About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Higher Mortality Rate Among African Americans With Common Forms of Head and Neck Cancers Attributed to Genetic Mutations

by Kathy Jones on December 9, 2013 at 6:41 PM
Font : A-A+

 Higher Mortality Rate Among African Americans With Common Forms of Head and Neck Cancers Attributed to Genetic Mutations

Genetic mutations, in combination with chemical alterations that affect gene activity, could be the reason for a 18 percent higher death rate among African Americans who are diagnosed with the most common form of head and neck cancer compared to whites who have the same cancer.

The so-called survival gap persists, the team says, despite decades of steep declines in deaths from head and neck squamous cell carcinomas among Americans of all races, which is largely attributed to the sharp drop in smoking since the mid-1970s.

Advertisement

The team's latest analysis of tumor tissue and blood samples from 60 black and 168 white men and women with the disease is believed to be the first and most in-depth analysis of the genetic and epigenetic origins of such common cancers of the lip, mouth, tongue and throat based on race.

Researchers plan to present the study findings on Dec. 7 in Atlanta at the Sixth American Association for Cancer Research Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved. More than 30,000 Americans die annually from some form of head and neck squamous cell carcinoma.
Advertisement

According to lead study investigator and genomics epidemiologist Rafael Guerrero-Preston, Dr.P.H., his team's research findings represent what could be the final piece in the survival-gap mystery, adding to such well-studied and well-known contributing factors such as poor education, poverty, limited access to health care and untimely access to treatments.

"Our study results are essential to understanding and eventually remedying head and neck cancer survival disparities between races," says Guerrero-Preston, an assistant professor in otolaryngology - head and neck surgery at the Johns Hopkins University School of Medicine and its Sidney Kimmel Comprehensive Cancer Center. "The genetic and epigenetic changes we identified can be used for improved risk assessment, early detection, targeted therapy and patient follow-up for people of all races."

Among the study's key findings were some 317 epigenetic modifications significantly more prevalent in people with head and neck cancers and the four most common that were more prevalent in blacks and whites, primarily in a half-dozen biological pathways.

One pathway, called TP53, was linked by earlier research from the same Johns Hopkins team to increased rates of head and neck cancers in people of all races. Another, NOTCH1, has only recently been tied to squamous cell carcinomas.

Researchers also found several related epigenetic alterations - molecular modifications of nuclear DNA -- in the PAX pathway, primarily at PAX1 and PAX5, where a chemical process called methylation blocks tumor-suppressing gene activity, silencing the gene.

In their study, survival outcomes for all head and neck cancers were worse for blacks, with some 20 percent fewer blacks surviving past five years than whites.

Three out of 10 people of either race with head and neck cancer and both a TP53 mutation and PAX5 methylation do not live as long as people who have had head and neck cancer and just a TP53 mutation.

Survival outcomes after five years were two and a half times worse for blacks with PAX5 methylation than whites. Indeed, people of either race with PAX5 methylation did not live as long as those without.

Moreover, the team's analysis showed that these related molecular changes were dependent on where the original tumor arose.

For cancers originating at the back of the mouth, or oropharynx, blacks had significantly more NOTCH1 mutations than whites, at 67 percent and 14 percent, respectively. Outside the oropharynx, however, the reverse occurred, with no blacks and 18 percent of whites having a NOTCH1 mutation. PAX1 and PAX5 epigenetic alterations were similarly reversed depending on tumor location, with PAX1 methylation in 52 percent of blacks and in 62 percent of whites in the oropharynx, compared to 70 percent and 60 percent, respectively, for tumors originating elsewhere in the head and neck.

TP53 mutations, on the other hand, were significantly higher in blacks than in whites, regardless of tumor site.

As part of the team's analysis, which took three years to complete, researchers decoded and then validated the cancer genetic profiles of all study participants, mostly from the Baltimore region, and then compared the results with genetic information obtained from 279 squamous cell carcinoma tissue samples in The Cancer Genome Atlas, a national database.

Guerrero-Preston says that further examination of the genetic and epigenetic modifications will be required before precise survival numbers, measured in months or years, can be ascribed to any particular genetic mutation or combination of changes. Such detailed findings, he says, will require some 200 additional study volunteers in order for the study to be scientifically accurate.

Guerrero-Preston plans to not only continue his genetic analyses in blacks, but also to study head and neck cancer disparities in Latinos, another ethnic group in which a survival disadvantage, although smaller, persists versus whites.

"Our research goal is to figure out how all of these ethnically predisposing genetic markers interact; how they turn off and on in response to environmental stimuli such as inflammation and lifestyle factors including smoking and nutrition, and how they trigger cancers of the head and neck," says Guerrero-Preston.



Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
First Dose of COVID-19 Vaccines May Improve Mental Health
Printed Temperature Sensors help with Continuous Temperature Monitoring
Health Benefits of Giloy
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Genetics and Stem Cells Cancer Gilbertís Syndrome McArdle Disease Christianson Syndrome Common Lifestyle Habits that Cause Diseases Health Benefits of Dandelion Plant Head and Neck Cancers Immune Checkpoint Inhibitors for Cancer Treatment Non-Communicable Diseases 

Recommended Reading
Genetic Testing of Diseases
Genetic testing helps to confirm a genetic condition in an individual and involves q complex ......
Epigenetics
In the recent years 'epigenetics' represents inheritable changes in gene expression that do not ......
Importance of Health Screening Tests
Health screening, along with a healthy diet and exercise, is necessary for good health and a higher ...
Christianson Syndrome
Christianson syndrome is a condition that occurs due to mutations (abnormal changes) in the gene SLC...
Common Lifestyle Habits that Cause Diseases
Cigarette smoking, unhealthy diets, overuse of alcohol, and physical inactivity are some of the most...
Gilbertís Syndrome
Gilbertís syndrome is a common, mild liver disease in which a liver enzyme required to process bilir...
Head and Neck Cancers
Head and neck cancers usually occur in the squamous cells lining the moist, mucosal surfaces inside ...
Health Benefits of Dandelion Plant
What is dandelion? Dandelion greens are nutrition powerhouses with a wide range of health benefits. ...
Immune Checkpoint Inhibitors for Cancer Treatment
Immune checkpoint inhibitors are promising drugs to treat a variety of cancers and the FDA has appro...
McArdle Disease
McArdle disease is a genetic disorder in which the body cannot breakdown glycogen in the muscles. It...
Non-Communicable Diseases
Non-Communicable Diseases (NCDs) are a group of chronic non-infectious diseases which include Cardio...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use